Cox, 28, of the 1400 block of West 85th Street, was charged with two counts of first-degree murder, attempted murder and a parole violation, according to police documents. Earlier this month, police charged 18-year-old Antonio Lewis, the alleged shooter, in the double homicide.

Cox and Lewis are accused of killing Chavonne Brown, 31, and her 5-year-old son, Sterling Sims, on June 28 at their home in the 5300 block of South Winchester Avenue.

About 2:39 a.m. that Friday, Cox and Lewis went to Brown's home, where Cox knew Lewis planned to commit a burglary, Cook County Assistant State's Attorney Latoya Croswell said during Cox's bond hearing on Sunday.

Lewis went inside and shot Brown twice in her head and then went to a bedroom, where he shot Sterling in his left eye, according to Croswell and police documents.

Sterling's 11-year-old brother was inside the home at the time of the shooting and would have been killed if Lewis' gun had not jammed at the time, family said in June.

After the shootings, Lewis fled with Cox as the getaway driver, and the two divvied up the proceeds from the robbery, Croswell said in court.

Later the same day, Cox called someone and offered half a pound a weed in exchange for killing Lewis, Croswell said. The hired killer, who has not been charged, agreed, the assistant state's attorney said.

Cox then told Lewis he thought they were getting "heat" for the murders and said he'd help Lewis find a gun and get out of a town, according to Croswell.

Cox, Lewis and the contracted killer all went to a spot where Lewis apparently thought he was to receive the gun promised to him, according to Croswell.

Instead, he was shot 11 times by the person contracted to kill him as Cox stayed in a car, according to Croswell. The shooting happened in 2800 block of West Arthington Street about 9 p.m., police had said.

But Cox and the hired killer were unsure if Lewis was dead, so Cox grabbed a knife and went to finish the job, Croswell said.

Cox tried to stab Lewis, but the knife bent, so Cox instead stomped on Lewis' head, Croswell said. Cox then saw police in the area and took off, Croswell said.

Lewis was taken to Mount Sinai Hospital with bullet wounds to his his neck, buttocks and groin, police had said. He was charged earlier this month. An update on his condition was not immediately available Sunday.

Police identified Cox as an accomplice during the course of the investigation, cops said. When they went to make a parole check on Cox, they found him hiding under a bed in another home, according to police documents. They arrested him Friday night, according to the documents.

Cox admitted to police that he was the getaway driver for Lewis, and he also admitted to hiring someone to kill Lewis, according to Croswell.

The person allegedly hired to murder Lewis has not been charged but did receive the weed, Croswell said.

Cox was previously convicted of aggravated battery with a firearm, for which he was taken into custody in 2004, according to Illinois Department of Corrections records. He was paroled in 2010, according to the records.